Patent GB-716329-A (GB)
Title: Improvements in or relating to pressure vessels
IPC: B01J3/03
Filed: 1951-09-28
Abstract: 716,329. Pressure resisting doors. STONE, F. W., and WATKINS, G. G. Sept. 29, 1952 [Sept. 28, 1951], No. 22752/51. Class 123(1) A pressure vessel 1, e.g. for sterilizing surgical instruments, has a seating ring 3 with sealing faces 4 thereon, surrounding an opening 2 in the vessel 1, and a door 5 having complementary sealing faces and relatively displaceable parts associated with the door 5 and ring 3 for latching and unlatching the door 5 in closed position, and means, e.g. a handle 18, 19 operating a nut 10 and screw 9, for moving the opposed sealing faces into and out of engagement whilst the door 5 is latched. The door 5 is latched by rotating a plate 13 to bring projections 13a thereon into slots 14 in a shroud 15 attached to the ring 3. The door 5 is carried by trunnions 21 on a forked arm 22 pivoted at 28 to an arm 27 pivoted at 29 to a bracket 30 fixed to the shroud 15, stops 23, 24 acting respectively to limit the swing of the door 5 on the arm 22, and the inward movement of the door 5 about the pivot 28. By this construction final approach of the door 5 to the ring 3 is axially of the door 5. Final tightening of the door 5 is by rotation of the handle 18 on the squared end 20 of the screw 9 which rotates in the ball race 12 to advance the nut 10, rotation of which is prevented by studs 11 on the door 5. The door 5 cannot be opened until a predetermined sequence of operations has been carried out, as described below. A rod 32, Fig. 3, engages a slot in the perimeter of the plate 13, which hence cannot be unlatched until the rod 32 is raised by a spring 33, and this is prevented until de-pressurizing, draining, and, if desired, flushing, have been carried out. In Fig. 3 pressure is being applied to the vessel 1 through the action of an arm 37 on a valve rod 38, the rod 32 being held down by the engagement of an abutment 35 thereon by an arm 34. The pressure in the vessel 1 is cut off by raising a lever 36 to a horizontal position, Fig. 4 (not shown) which (a) moves the arm 37 downwardly to release the rod 38 and (b) moyes the arm 34 upwardly, Fig. 2 (not shown). The rod 32 is still held down, however, since a pivoted catch 43 thereon is not aligned with a slot 144 on a fixed plate 44. A second lever is now operated to move an arm 42 downwardly, thereby aligning the catch 43 and the slot 144, simultaneously opening a drain for the vessel 1. The rod 32 is still held by the arm 42 engaging an abutment 45 on the catch 43. Flushing of the vessel 1 may now be carried out if desired by raising the lever 36 to an upwardly inclined position, Fig. 5 (not shown), the rod 32 being still held by the arm 42. The lever 36 is then restored to the horizontal position and the second lever restored to its original position to close the drain and remove the arm 42, thereby allowing the rod 32 to move up to permit unlatching of the plate 13. The two levers are interconnected by discs 46, 47 having interengaging cut-outs 48, 49 such that in Fig. 3 the disc 47, i.e. the second lever, cannot be rotated until the disc 46, i.e. the lever 36, is moved, and only then can flushing be carried out.